1. Field of the Invention
The present invention relates to a specimen container for storing a specimen such as blood employed in the field of clinical tests or the like, and more particularly, it relates to a specimen container storing a small quantity of specimen such as a control sample employed for quality control of an automatic analyzer.
2. Description of the Background Art
Specimen measurement from transport of a specimen to pretreatment and multiple measurement has become automated with recent increase in the measurement number of patient specimens in the field of clinical tests. Measurement of a control sample for performing quality control of an automatic analyzer also has become automated.
In a case where quality control is performed in an automatic analyzer such as an automatic blood cell counter, a control sample such as control blood is stored in a predetermined specimen container to be used. The specimen container storing the control sample is placed on a specimen rack together with a plurality of specimen containers storing the patient specimens and is provided to the automatic analyzer. A bar code label for identifying the patient specimen is stuck on each specimen container storing the patient specimen, and a bar code label for identifying the control sample is stuck on the specimen container storing the control sample. The bar codes of these bar code labels stuck on the specimen containers are read by a bar code reader of the automatic analyzer, and it is identified whether the specimen stored in the specimen container is the patient specimen or the control sample.
At the time of measurement, in order to uniformly disperse components such as blood cells in the specimen container, the blood cells and the like in the specimen container are stirred. Thereafter, a suction tube is inserted into the specimen container, and sample suction and component measurement such as counting of the blood cells are performed.
A small quantity of the control sample is enough as the quantity of the specimen required for the measurement as compared with that of the patient specimen, and hence a volume of a normal specimen container is too large for the quantity of the control sample. Thus, when the control sample stored in the normal specimen container is stirred, the moving quantity of the control sample in the specimen container is increased. Consequently, there is a possibility that the specimen is damaged. The control sample is used (measured) a plurality of times dissimilarly to the patient specimen measured only once. Thus, the control sample is damaged due to stirring at the plurality of times, and this can greatly affect quality of the control sample. The volume of the specimen container is large as compared with the quantity of the control sample, and hence the rate of the control sample adhering and remaining on an inner surface of the specimen container is increased. Consequently, the stirring is conceivably insufficient.
When the specimen container itself is downsized depending on the quantity of the control sample, on the other hand, the size of the specimen container is different from that of the normal specimen container, and hence there is a possibility that a measuring operation such as stirring or suction can not be performed in a manner similar to that of the normal specimen container storing the patient specimen. Thus, an inconvenience that the control sample can not be automatically measured is caused. Further, an area for sticking the bar code label on an outer side surface of the specimen container can not be ensured, and whether the specimen stored in the specimen container is the patient specimen or the control sample can not be automatically identified by the bar code. This also makes automatic analysis difficult.
Japanese Utility Model Laying-Open No. 5-36364 discloses an invention of a “specimen container” as a container for storing a small quantity of specimen. This specimen container is a specimen container constituted by a cap and a cylindrical container body opened/closed by the cap and having an outer shape similar to the normal specimen container, in which a bottom of the container body is formed in the middle of the cylindrical body. In other words, the specimen container has a so-called push-up bottom, and the volume of storing the sample is smaller than that of the normal specimen container. According to this structure, the moving quantity of the sample in the specimen container is small even when a small quantity of the specimen is stored and stirred, and hence damage to the specimen is reduced. The outer shape of the specimen container is not downsized, and hence the specimen in the specimen container can be stirred in a manner similar to that performed for the normal specimen container by the automatic analyzer, and the area for sticking the bar code label can be ensured on the outer side surface.
In the aforementioned specimen container described in Japanese Utility Model Laying-Open No. 5-36364, however, while the specimen in the specimen container can be stirred in the manner similar to that performed for the normal specimen container and the bar code label can be stuck, the specimen container is formed to have the push-up bottom shape and hence a forward end of the suction tube may collide with the push-up bottom portion when the suction tube is inserted from above by the automatic analyzer. In order to avoid such a problem, means for adjusting a depth for inserting the suction tube depending on the shape of the specimen container is required and a structure of the analyzer is complicated.
Thus, in a case of a small quantity of the specimen sample, reduction in the volume of the specimen container is demanded in order not to damage and ununiformly stir the specimen sample. Further, the depth of the specimen container must be ensured so as not to collide with the bottom portion of the suction tube, while ensuring a height enough to smoothly perform the operation such as stirring by the automatic analyzer. The specimen container satisfying all of these demands is desired.